Add "standard" cogment release scripts

[cloderic]

Description

Introduce release scripts common with other Cogment project, to be ready for release.

Checklist:

• (was already failing) I have run the pre-commit checks with pre-commit run --all-files (see CONTRIBUTING.md instructions to set it up)
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• N/A I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes